I think you're also being sarcastic :) Websites did this 15 years ago (miss the HTMLX compliant button at the bottom of the page), and now in large part do not.
I made my first website 22½ years ago. Even as a raw beginner, I knew it was considered sloth and Very Bad Form Indeed not to specify image size in my markup.
"Oh wow, 22 years ago! This guy must be... my... age... Shit."
Everything that is standard recommended practice in modern web design is Very Bad From, whether or not it is sloth.